1221201988 has 12 divisors (see below), whose sum is σ = 2167204032. Its totient is φ = 602000840.

The previous prime is 1221201979. The next prime is 1221202007. The reversal of 1221201988 is 8891021221.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2149720 + ... + 2150287.

It is an arithmetic number, because the mean of its divisors is an integer number (180600336).

Almost surely, 2^1221201988 is an apocalyptic number.

It is an amenable number.

1221201988 is a deficient number, since it is larger than the sum of its proper divisors (946002044).

1221201988 is a wasteful number, since it uses less digits than its factorization.

1221201988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4300082 (or 4300080 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 34.

The square root of 1221201988 is about 34945.7005653056. The cubic root of 1221201988 is about 1068.8805329753.

The spelling of 1221201988 in words is "one billion, two hundred twenty-one million, two hundred one thousand, nine hundred eighty-eight".